Selecting system



June 13, 1944. N. D. NEWBY 2,351,360

SELECTING SYSTEM Filed D ec. a1, 1942 2 Sheets-Sheet 1 su. c (244) FIG!MASTER C005 20 A 5' INVENTOR 8 Q5; N.D./VEWBV A T TORNEY Juhe13, 1944. ND NEWQY 2,351,360

SELECTING SYSTEM Filed Dec. 31, 1942 2 Sheets-Sheet 2 7 I H H "Rh 3 T 45 5 /2 l3 /4 9 g 4? L l I l I I I I lNl/ENTOR By N.0.NEWBV ATTORNEYPatented June 13, 1944 UNITED STATES PATENT orrucs NealD. Newby, Leonia,N. 1

Telephone Laboratories,

las is o to l Incorporated, New

York, N. Y., a corporation ot'New York Application December 31, 1942,Serial No. 470,816

9 Claims.

This invention relates to selective systems and has for its object toprovide code selective arrangements which may be controlled by thestandard telephone dial.

In the well-known code selective systems employed for train dispatching,a plurality of selectors are connected to a single conductor or pair ofconductors. Each selector has a set of contacts aranged in accordancewith a code to hold the selector against release whenever it is advancedto such a code position. Although every selector operates in response toeach digit transmitted over the line, only a limited number of selectorswill be held in their advanced position at the end of the first digit ofthe code. In response to a second digit, a smaller number will be inposition to be held and at the end of the series or digits only oneselector will have been placed in position to control its signal.Standard train dispatching systems employ pulses of alternate positiveand negative polarities and, therefore, require rather complicatedtransmitting equip-- ment.

In accordance with the present invention, a selector is provided whichmay be operated under control of the ordinary telephone dial.

Furthermore, the invention contemplates a se lector comprising a seriesof resilient balls having two positions of rest, with means under thecontrol of dial pulses for driving one ball at a time from one positionof rest to the other together with means including the balls themselves,effective after reception of code numbers of pulses, for holding theballs in their alternate positions.

More specifically, the balls of the selector are composed of magneticmaterial and are held in their alternate positions under the control ofan electromagnet, the circuit of said electromagnet being closed throughthe balls themselves if, and only if, the corresponding code digits havebeen e s These and other features of the invention will be more clearlyunderstood from a consideration of the following description inconnection with the drawings in which:

Fig. 1, shows three stations of a train dispatch ing system employingselectors of the present invention and Fig. 2 shows the structure of theselector in detail. The same reference numerals have been applied to thevarious parts of the selector wherever they'loccurbut in the circuit ofFig. 1 hundrds digits have been prefixed tothe reference numerals inorder to distinguish between the stations.

The structure of Fig. 2 will first be described. A somewhat similardevice used for counting is disclosed in United States Patent 2,292,489,granted to G. R. Stibitz on August 11, 1942. Secured on a base I are twoL-shaped brackets 3 and 4 held in place by screws 5 and 6. The screw 6also holds in place a soldering lug 42. Between the brackets 3 and 4 anelectromagnet 40 is held in place by screws 1 and 8. The magnet 40consists of a Ushaped core 3 having two legs I0 and II, and threewindings [2, I3 and I4. Between the legs I0 and I I are mounted a set ofeleven resilient magnetic balls I 5 to 25, each ball carried by aspring, such as spring 26. The springs are insulated from one anotherand from the legs I0 and I I of the magnet core 9 by spacers ofinsulating material 21 and are held in place by means of screws 28 whichextend through the legs of the magnet, the mounting springs and thespacers of insulating material. Outside of leg I0 and suitably insulatedtherefrom and from each other are mounted an electromagnet 50, having aC- shaped core 29 and two windings 30 and 3|, together with a spring 32carrying a ball 33 which serves as the armature for magnet 50 andcontact carrying springs 43 and 44 which cooperate with contacts carriedby spring 32. Balls I5 to 25 and 33 are arranged so that their centerslie in alignment. The screws 28 which hold the springs 26 in place alsopass through one leg of the core 29 and through springs 32, 43 and 44and through the insulation between them, thereby retaining the structurein operative relationship. Screws 28 are insulated from the springs andcore members in any suitable manner.

The end of leg II has been shown broken away to disclose a contactarrangement carried by it. Screw 35 extends through an opening in leg IIand terminates in a contact member 34. Screw 35 is insulated from leg IIby means of insulating bushing 31 and is held firmly in place by meansof nut 38. A soldering lug H is clamped between nut 36 and the bushing31. The springs 26 terminate in soldering terminals by which they may bewired together by wire loops, such as loops 38 and 39. V

Fig. 1 shows three of a plurality of stations comprising a traindispatching system which are connected together by line wires I52 andI53. Each station is equipped with the same apparatus, for example,station A includes a selector I5I like that shown in detail in Fig. 2, atelephone set IIiO, a dial I56 and a signal bell I BI. Both the selectorI 5| and the telephone set I60 are connected between the line wires I52and I53 but the telephone circuit is normally opened at the switchhookcontacts. Winding I30 of magnet I50 is connected to line wire I52 andwinding I3I is connected to line wire I53. When the subscriber at one ofthe stations, for example, station A, wishes to signal another station,he will first listen to determine that the line is not in use and thenoperate key I51, thereby closing a bridge across conductors I52 and I53through key I51 and dial I58, andcompleting an operating circuit for allof the magnets I50, 250, 350, etc.

draws ball I33 out of contact with leg IIO of magnet core I09. Inaddition it closes a circuit from ground through condenser I 58 oversprings I32 and I43 through winding II2 of'magnet ,l40 to battery,thereby setting up a charging circuit for condenser I58. Winding I I2 isenergized by this charging current which creates a magnetic flux throughthe balls II5 to I25, holdingthe balls against leg IIO. Similaroperations take place at all of the stations connected to conductors I52and I53.-

Assuming that station C is to be signaled, the subscriber at substationA will then dial the digits 2, 4 and 4, which make up the'code assignedto station C. At the first opening of the contact of dial I58,magnet-I50 is deenergized and releases spring I32 which falls backsharply, causing ball I33 to strike against leg I I and transmit animpact through balls I25 to H which causes ball I I5 tomove to the rightand come'to rest against contact I34. Due to the magnetic flux throughthe balls, ball II5 remains in its alternate position. I

With spring I32 in its normal position, a circuit is closed from groundthrough condenser I50, springs I32 and I44, through-winding II3 ofmagnet I40 to ground. Condenser I58, which has been charged, nowdischarges through the middle winding of magnet I40, maintaining themagnetic flux through the balls. The same action takes place at stationsB, C, etc.

When the-dial contact closes, magnet I50 again attracts spring I32 andrecloses the charging circuit for the condenser I58 through winding I I2of magnet I40. At the second opening of the dial, balls H8, 2"; and 3I6are also driven into their alternate positions.

After this the dial contacts remain closed for an interval while thesubscriber prepares to dial the next digit. Under this condition thecharging currentthrough the winding II2 would die down leaving magnet I40 deenergized. However, in the three stations shown, all of which havethe digit 2 as the first digit of their respective codes,

with two balls resting'against the contact carried by the right leg ofthe holding'magn'et core,

a circuit is closed which may be tracedin' the case of station A frombattery through winding II 4 of magnet I40, contact I34, balls H5 andH8, wire I39, balls II! to I25 to ground over core I09. -Therefore,magnets I40, 240 and 340 remain energized and hold the balls in positionduring the interdigital interval.

The subscriber now dials the second digit of the code of station C, thatis the digit 4, causing 3I'I, 3I8,3I9 and 320 to'be driven to the right.At the end of this digit aholding circuit'is completed for magnet340which may be traced from bat- 2,a51,sco

tablished for magnet I40. The same is true of station B so that, as soonas the charging current for condensers I58 and 258 ceases, magnets I40and 240 are deenergized and the balls of stations B and C return totheir normal position.

When now the third digit of the code of station C is dialed, that is,the digit 4, balls II5 to H8 at station A and balls 2I5 to 2I 8 atstation B, are driven to the right, while at station C balls 32I to 324are driven to the right. At station C, therefore, at the end of thethird digit, a circuit is on the line. Magnet I50 attracts spring I32and apparent? I V It is also to be understood'that' a selector employing a larger number of balls, 'for example twenty, might be used toprovide means for makclosed from battery through winding 3I4 of magnet340, contact 334, balls 3I5 to 324, inclusive,

winding of relay 362, ball 325 to ground through thejcore 309;; Relay362 operates in this circuit and closesan obvious circuit for bell 35Ithereby signaling'th subscriber at station C. When the subscriberrais'eshis handset in response to this signal, the circuit of the bell isopened and the bell is silenced. Conversation may now take place betweenthe subscribers at stations A and:'C.

At the end of thelast digit, the selector .pulse' magnets I50, 250 and350 are held operated due to the closure of the dial contacts and thecontinued closure of key I51. .In the'selector of station A, balls I I5to I I8 are held in their'altemate positions, at station B all the ballsare normal, while at station C balls 3 I 5 to 324 are held in theiralternate'positions. At any time afterthe subscriber of station C hasanswered, the subscriber at station-A may open his key I5'I therebyreleasing magnets I50, 250, 350, etc. at all stations.

At station A, ball I I9 is driven to the right, open ing theinterdigital holdingcircuit for magnet I 40 and, when the dischargecurrent for condenser I08 dies away, magnet I40 is'deenergized,

permitting all of the balls. I I5 to I25 to return to normalfl V Atstation 13, where .all the balls were restored at the end of the thirddigit, ball 2I5 is driven to the. right in response to the release ofmagnet 250, but, since no holding circuit is provided be-: tween balls 2I5 and 2I6, ball 2I5 returns to n'o'r mal as-soon as the condenser 258is discharged.

At station Cball 3251s 'driven'to the rightyalso" breaking thei'nterdigital holding circuit, permit -"v ting magnet340 todeen'ergize'on the decay of the condenser "discharge current and allofthe balls to return to normal. I

It is apparent that thestruct'ure of the presentinvention provides aconvenient'form of selector in which the selectors are arranged forrespond? ingtothe various codes-by merely changing the wiring betweenthe ball-mounting springs. The

' 'ionly limitation on the code is that the digit '1 may never be used."It'willalso'be; apparent that allf three stations may also be signaledby dialing either the group master code 28 or the general masterfcode 0(ten impulses), since an interdigital 1 holding circuit is provided forall of these stations with two balls or with ten balls at the right."The" arrangement of the selector wiring f or other'stafor other groupswill be tionsin this group and ing selections in a system including alarger hu ber of stations.

What is claimed is:

position at each pulse, a magnet for holding said balls in saidalternative position, means to energize said holding magnet duringtrains of pulses, means controlled by said balls to energize saidholding magnet between trains of pulses in accordance with the number ofballs in said alternative position at the end of each train of pulses, asignal, and means to operate said signal when a predetermined number ofballs are held in said alternative position at the end of a train ofpulses.

2. In a selecting device, a row of resilient magnetic balls in contactwith one another, pulse responsive means for delivering an impact to theball at one end of said row to drive one ball from the other end of saidrow into an alternative position at each pulse, a magnet for holdingsaid balls in said alternative position, means to energize said holdingmagnet during trains of pulses under the control of said pulseresponsive means, means controlled by said balls to energize saidholding magnet between trains of pulses in accordance with the number ofballs in said alternative position at the end of each train of pulses, asignal, and means to operate said signal when a predetermined number ofballs are held in said alternative position at the end of a train ofpulses.

3. In a selecting device, a row of resilient magnetic balls in contactwith one another, pulse responsive means for delivering an impact to theball at one end of said row to drive one ball from the other end of saidrow into an alternative position at each pulse, a magnet for holdingsaid balls in said alternative position, means to energize said holdingmagnet during trains of pulses under the control of said pulseresponsive means comprising a condenser and means for charging saidcondenser through said holding magnet and discharging it through saidholding magnet at each pulse, means controlled by said balls to energizesaid holding magnet between trains of pulses in accordance with thenumber of balls in said alternative position at the end of each train ofpulses, a signal, and means to operate said signal when a predeterminednumber of balls are held in said alternative position at the end of atrain of pulses.

4. In a selecting device, a row of resilient magnetic balls in contactwith one another, pulse responsive means for delivering an impact to theball at one end of said row to drive one ball from the other end of saidrow into an alternative position at each pulse, a magnet for holdingsaid balls in said alternative position, means to energize said holdingmagnet during trains of pulses, a circuit for energizing said holdingmagnet over said balls between trains of pulses, said circuit completedonly when predetermined numbers of balls are in said alternativeposition at the end of each train of pulses, a signal, and means tooperate said signal when a particular predetermined number of balls areheld in said alternative position at the end of a train of pulses.

5. In a selecting device, a row of resilient magnetic balls in contactwith one another, pulse responsive means for delivering an impact to theball at one end of said row to drive one ball from the other end of saidrow into an alternative position at each pulse, a magnet for holdingsaid balls in said alternative position, means to energize said holdingmagnet during trains of pulses, a circuit for energizing said holdingmagnet over said balls between trains of pulses, means to connectcertain of said balls in pairs to complete said circuit at the end ofeach train of pulses in accordance with predetermined codes, a signal,and means to operate said signal when a predetermined number of ballsare held in said alternative position at the end of a train of pulses.

6. In a selecting device, a row of resilient magnetic balls in contactwith one another, pulse responsive means for delivering an impact to theball at one end of said row to drive one ball from the other end of saidrow into an alternative position at each pulse, a magnet for holdingsaid balls in said alternative position, means to energize said holdingmagnet during trains of pulses under the control of said pulseresponsive means, a plurality of circuits for energizing said holdingmagnet between trains of impulses, said circuits extending through saidballs and completed only when a plurality of different numbers of saidballs are in said alternative position at the end of each train ofpulses in accordance with a predetermined code, said circuits becomingsuccessively effective in response to successive trains of impulses, asignal, and means for operating said signal when the number of ballsmoved into and held in said alternative position is equal to the totalnumber of impulses in all of said trains.

7. In a selecting device, a row of resilient magnetic balls in contactwith one another, pulse responsive means for delivering an impact to theball at one end of said row to drive one ball from the other end of saidrow into an alternative position at each pulse, a magnet for holdingsaid balls in said alternative position, means to energize said holdingmagnet during trains of pulses under the control of said pulseresponsive means, a plurality of circuits for energizing said holdingmagnet between trains of impulses, said circuits extending through saidballs and completed only when a plurality of different numbers of saidballs are in said alternative position at the end of each train ofpulses in accordance with a predetermined code, said circuits becomingsuccessively efiective in response to successive trains of impulses, anda signal in one of said circuits, said one circuit being completed whenthe number of balls moved into and held in said alternative position isequal to the total number of impulses in all of said trains.

8. In a selecting device, a row of resilient mag netic balls in contactwith one another, pulse responsive means for delivering an impact to theball at one end of said row to drive one ball from the other end of saidrow into an alternative position at each pulse, a magnet for holdingsaid balls in said alternative position, means to energize said holdingmagnet during trains of pulses, means to connect a plurality of pairs ofsaid balls together in accordance with a predetermined code, a circuitfor said holding magnet completed whenever one ball of a pair is in itsnormal position and the other ball of the pair is in its alternativeposition at the end of a train of pulses, said circuits being effectiveto prevent the return of said balls to their normal position betweentrains of pulses made up of corresponding numbers of pulses, and asignal, said signal operated over a particular one of said circuits ifthe total number of balls held in the alternative position equals thetotal number of pulses in all trains.

9. In a selecting device, a row of resilient magnetic balls in contactwith one another, pulse responsive means for delivering an impact to theball at one end of said row to drive one ball from is in its alternativeposition at the end of a train 10 of pulses, said circuits becomingsuccessively ef fective to prevent the return of said balls to theirnormal position between successive trains of pulses made up of codenumbers of pulses, and a signal, said signal operated over a particularone of said circuits if the total number of balls held .in thealternative position-equals the total number of pulses in all trains.

NEAL D. NEWBY.

